MPP-Solar LVX-6048

[jsheffer]

You would have to open the unit to verify (I am not opening my two ), but I am betting there is a bunch of mosfets doing the conversion and then dumping the power into the auto transformer to keep everything balanced. I doubt the conversion board is full of LF transformers.

I am not an inverter engineer, so take this with a grain of salt...

I think that the LVX is a type of "hybrid" if you will... A HF inverter with the Auto transformer to "simulate" characteristics of a LF inverter...

 

[insulso1]

jsheffer, I have not. I have dedicated wire connected to a ground bar.... your idea would be to use no ground on the inverter?

All, As of now no fault during today's solar production.

 

[iamrich]

I am just starting, so hoping I don't run into issues at all

 

[euphonius]

I am just starting, so hoping I don't run into issues at all

View attachment 114808

Not to press, but when will your house be finished? When do you expect to be powering these up? Off-grid or grid-tied? I don't see the paralleling boards in your inverters. Are you not stacking them in parallel? So many questions...

 

[iamrich]

Not to press, but when will your house be finished? When do you expect to be powering these up? Off-grid or grid-tied? I don't see the paralleling boards in your inverters. Are you not stacking them in parallel? So many questions...

Hoping in the next month or two.

Grid tied, but no back feed for now
No parallel. Each inverter feeds one sub panel

I plan to do a write up to not take away from other threads, but it will be a while.

 

[nc73]

I am just starting, so hoping I don't run into issues at all

View attachment 114808

that's how these are made to run. Parallel just isn't in the cards for these. Mine will be backup to the EG4's if it ever gets here.

 

[nc73]

Ok, don't chew me out here ok?

I know it isn't safe...but the last two weeks my single unit has been running flawlessly, only after lifting the ground of the inverter out put to the sub panel. My unit is mounted in a metal quonset hut building, everything is basically bonded to ground. My house is old and so is the grid service entrance (old square D QO) I know I have more than one spot where N is bonded to G but I would have to tear everything out and start over to fix it. (the old half of the house is an old 2 wire system, no ground wire among other issues...) Landing the G from the inverter was causing all sorts of headaches; flickering lights, high bus faults, inaccurate readings on the solarpower app, funny humming/rattling noises from the inverter, ect... I tried the capacitor trick nc73 was telling us about, I tried 14uF, 16uF, even a 50uF capacitor on both the grid and inverter side L1-L2... no change, it didn't help. When you guys started talking about the current sensing wires for your parallel units, I half way wondered if the ground loop is what is confusing our inverters. If the current sensors are picking up transient currents because of the ground loop issues, then the control circuit would go haywire causing all sorts of problems. This is just me thinking out loud again, hoping we might figure something out...

I know that it has been discussed extensively all over, but there still seems to be confusion on the subject of the N-G bond inside our inverters. I would like to get a second LVX6048 and run them in parallel, but it seems that no one has figured it out yet, and so I am hesitant to do it.

I know its not safe to run equipment without a ground, but for testing purposes, it might be worth a try....

@ Ian30, Insulso1, and Boondox and your stepson, have you guys tried running your units in parallel without the GROUND landed?

please don't try it if you don't feel safe doing it!

If it needs to have certain requirements met I'm sure Ian would've told us by now. Wait until MPP figures it out. Could be a long wait though,..

 

[insulso1]

End of day report…
No faults today, no light flickering. Pv production 9.76k. No hearing the weird humming… no power rest reported by the wife (not a reliable source)

Will keep reporting

 

[nodoze]

I change to SUB from SBU and it solve the fault....... but its like the inverter does not like to see grid voltage when charging from solar. BTW I only have 2.2k of solar nothing big for now. (1 string of 6 @ 380w).
I am going to update the firmware first and check if that helps. if not I will switch inverters.

Is SUB short for providing power to loads priority-wise first from Solar, then Utility, then Battery?

If you have grid power & set SUB & the sun goes down does the inverter switch to just bypass mode to provide power from Utility only and shut down the inverter & thus have less Watts consumption overnight?

 

[iamrich]

that's how these are made to run. Parallel just isn't in the cards for these. Mine will be backup to the EG4's if it ever gets here.

I am just hoping they will do what I am asking of them. The house I am building is basically two sides, 800sq ft, and 1550 sq ft. All Electric, but I put the water heater, both stoves, and the laundry (washer and dryer) on the main grid panel. The sub panels have the rest (lights, AC/Heater, microwave, tv's, computer (s), etc. It will be interesting to see if I can run it all on 6000w. If it fails, the plan was to just add another unit in parallel, but maybe now I would move one unit to my garage to upgrade the LV2424 and then get something bigger (Growatt 12k maybe) to replace it. Worst case I just jump 100amp from the main panel to the subs while I figure it out. I am not trying to get rid of the grid, I just want to reduce consumption as much as possible and be able to operate if the grid goes down. Looking at probably 30kwh of battery and 15kw of panels to start. Should be fun, especially if I can sell my current house now that the housing market hasn't apparently started to cool off.

 

[nc73]

I am just hoping they will do what I am asking of them. The house I am building is basically two sides, 800sq ft, and 1550 sq ft. All Electric, but I put the water heater, both stoves, and the laundry (washer and dryer) on the main grid panel. The sub panels have the rest (lights, AC/Heater, microwave, tv's, computer (s), etc. It will be interesting to see if I can run it all on 6000w. If it fails, the plan was to just add another unit in parallel, but maybe now I would move one unit to my garage to upgrade the LV2424 and then get something bigger (Growatt 12k maybe) to replace it. Worst case I just jump 100amp from the main panel to the subs while I figure it out. I am not trying to get rid of the grid, I just want to reduce consumption as much as possible and be able to operate if the grid goes down. Looking at probably 30kwh of battery and 15kw of panels to start. Should be fun, especially if I can sell my current house now that the housing market hasn't apparently started to cool off.

6k is enough if you watch what you run at the same time. That's what I'm having to do with mine. With the 2 EG4's I won't have to worry about what I turn on at the same time. I'm thinking of another 15k battery too but it might be cheaper for me to use grid for those times where the battery won't last overnight. I dunno, interest rates are pretty close to 7. Values are dropping...

 

[jsheffer]

jsheffer, I have not. I have dedicated wire connected to a ground bar.... your idea would be to use no ground on the inverter?

All, As of now no fault during today's solar production.

With my setup, I'm finding it near impossible to eliminate ALL N-G bonds except one in the system. I just discovered that these inverters really DO NOT like ground loops! The only way for me to stop the weird behavior on my lvx6048 was to eliminate the ground loop. Lifting the ground, as an experiment, to see if the weird behavior goes away or gets worse is just that; an experiment. I figured, you might think "what the heck, I could try that, and see if anything changes." It's really up to you, like I said: "if you don't feel safe doing it, you don't have to" I knew that lifting the ground was not a good idea, but when I was able to "remove" the ground loop on the inverter's side of the system, all my problems went away.

 

[insulso1]

Day 2. Solar production 10.6k. No faults, still using both inverters in parallel with one of them connected to all three power sources.

Looking good

 

[nc73]

Day 2. Solar production 10.6k. No faults, still using both inverters in parallel with one of them connected to all three power sources.

Looking good

So you followed different wiring diagram and only used 1 inverter to provide 3 power sources. Of course firmware update too. Tempted to try this out since I was going to just use the 1 inverter for solar array anyways. Unfortunately I have already bought all the wires and accessories for the EG4. I will give Signature Solar another week or 2 to come through with the order otherwise I will have to find an alternative. If only the idle consumption wasn't so high on the lvx, with 2 running.

 

[euphonius]

Day 2. Solar production 10.6k. No faults, still using both inverters in parallel with one of them connected to all three power sources.

Looking good

Very encouraging, insulso1!! Just recapping what you've done, and please correct me if I'm wrong, you:

• ensured there was a single neutral-ground bond across the system
• upgraded the firmware to the latest (06?)
• maintained a grid tie, but use the tie only to charge your batteries, not to backfeed the grid
• abandoned the balancing cable diagram of the instruction manual and wired the two inverters together according to the approach Ian Roux showed in his "paralleling LVX6048" youtube. (How were these different?)
• reprogrammed the inverter charging protocol to "sub" from "sbu" (??).

Ian Roux suspects that some people paralleling the LVX6048s are having problems because their battery bank is too small. How big is your battery bank? Do you mind showing us how you've paralleled them to the inverters?

Given that you've got the grid as a backup, you probably are less interested in charging from generator that us off-gridders, but I'm curious whether you've tried this yet and how you've wired the "AC in" circuit.

Thank you so much for the daily updates! Kindly keep them coming!

 

[insulso1]

It just change the setting from SUB to SBU on its own!!! ?

 

[nc73]

It just change the setting from SUB to SBU on its own!!! ?

Oh boy here we go so it's not solved.......i made a good move than that is one of the symptoms btw, changes settings on it's own.

 

[nc73]

Ian Roux suspects that some people paralleling the LVX6048s are having problems because their battery bank is too small. How big is your battery bank? Do you mind showing us how you've paralleled them to the inverters?

I highly doubt it's the batteries. Otherwise MPP would've said so. If they aren't low they should be fine unless it's a tiny duracell battery or something

 

[nc73]

Do what iamrich did, run them separately. Yes you will need another subpanel etc but you will have less headaches and won't cause a fire if it decides to blow up your batteries by overcharging it. Just my 2 cents.

 

[insulso1]

Ok so here is what I have done…

• ensured there was a single neutral-ground bond across the system my grounds are all bonded to a ground bar outside the house
• upgraded the firmware to the latest (06?) firmware updated to 6306
• maintained a grid tie, but use the tie only to charge your batteries, not to backfeed the grid no back feeding the grid. Just use the grid as back up when my batteries are low. I only have a total of 5.3kw of solar. Now Iam adding another 3kw to fully charge my batteries every day.
• abandoned the balancing cable diagram of the instruction manual and wired the two inverters together according to the approach Ian Roux showed in his "paralleling LVX6048" youtube. (How were these different?) look ? on my previous post. I posted the image of the difference between the diagram on LVX-6048 manual vs the diagram that is included with the paralleling kit… in summary I am following the paralleling manual
• reprogrammed the inverter charging protocol to "sub" from "sbu" (??). The comment I made regarding sub vs sbu was related to the homing and the faults.. since I changed the balancing cables this does not seems to make a difference anymore.

How big is my battery bank?

1. 8 simpliphi 3.8k. (30kw)
2. 1 PR energy of 8k

Total battery storage 38kw. Here in Puerto Rico I wanted to be able to run 3 days with little to no sunshine or grid power for charging. That just proved to be very useful 2 weeks ago with Storm Fiona knocking out the grid for 7 days..